Epigenetic drift explains why the aging intestine becomes more vulnerable to cancer
Researchers from the Leibniz Institute on Aging - Fritz Lipmann Institute (FLI) in Jena, Germany, the Molecular Biotechnology Centre (MBC) in Turin and the University of Turin, Italy, have discovered a fundamental mechanism of aging in the gut. Over the course of life, a specific form of epigenetic aging - known as ACCA drift - accumulates in intestinal stem cells. This leads to the shutdown of key genes through hypermethylation . The drift spreads across the intestinal crypts and is caused by a combination of age-related inflammation, weakened Wnt signaling, and impaired iron metabolism, which affects the activity of DNA-modifying enzymes. The findings provide new explanations for why the risk of colorectal cancer increases with age and which molecular processes are involved. The human gut renews itself faster than any other tissue: every few days, new cells are created from specialized stem cells. However, as we get older, epigenetic changes build up in these stem cells. These ...